<?php
/**
 * Created by PhpStorm.
 * User: liuxin
 * Date: 2018/1/29
 * Time: 下午4:17
 */
namespace common\components;


class Des
{

    public static function decrypt($encrypt_str, $key)
    {
        $cipher = MCRYPT_DES;
        $modes = MCRYPT_MODE_CBC;
        $iv = sprintf("%c%c%c%c%c%c%c%c", 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF);
        $str_encrypt = base64_decode($encrypt_str);
        $str_decrypt = @mcrypt_decrypt($cipher, $key, $str_encrypt, $modes, $iv);
        $slice = ord($str_decrypt{strlen($str_decrypt) - 1});
        $str_decrypt = substr($str_decrypt, 0, -1 * $slice);
        return $str_decrypt;
    }

    public static function encrypt($input, $key)
    {
        $cipher = MCRYPT_DES;
        $modes = MCRYPT_MODE_CBC;
        $iv = sprintf("%c%c%c%c%c%c%c%c", 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF);

        $block = mcrypt_get_block_size($cipher, $modes);
        $pad = $block - (strlen($input) % $block);
        $input .= str_repeat(chr($pad), $pad);
        $encrypted_data = @mcrypt_encrypt($cipher, $key, $input, $modes, $iv);
        return base64_encode($encrypted_data);
    }

    var $key;
    var $iv;
    public function __construct($key, $iv){
        $this->key = $key;
        $this->iv = $iv;
    }

    public function desencrypt($input){
        $size = mcrypt_get_block_size(MCRYPT_DES,MCRYPT_MODE_CBC); //3DES加密将MCRYPT_DES改为MCRYPT_3DES
        $input = $this->pkcs5_pad($input, $size); //如果采用PaddingPKCS7，请更换成PaddingPKCS7方法。
        $key = str_pad($this->key,8,'0'); //3DES加密将8改为24
        $td = mcrypt_module_open(MCRYPT_DES, '', MCRYPT_MODE_CBC, '');
        if( $this->iv == '' )
        {
            $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        }
        else
        {
            $iv = $this->iv;
        }
        @mcrypt_generic_init($td, $key, $iv);
        $data = mcrypt_generic($td, $input);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        $data = base64_encode($data);//如需转换二进制可改成  bin2hex 转换
        return $data;
    }

    public function desdecrypt($encrypted){
        $encrypted = base64_decode($encrypted); //如需转换二进制可改成  bin2hex 转换
        $key = str_pad($this->key,8,'0'); //3DES加密将8改为24
        $td = mcrypt_module_open(MCRYPT_DES,'',MCRYPT_MODE_CBC,'');//3DES加密将MCRYPT_DES改为MCRYPT_3DES
        if( $this->iv == '' )
        {
            $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        }
        else
        {
            $iv = $this->iv;
        }
        $ks = mcrypt_enc_get_key_size($td);
        @mcrypt_generic_init($td, $key, $iv);
        $decrypted = mdecrypt_generic($td, $encrypted);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        $y=$this->pkcs5_unpad($decrypted);
        return $y;
    }

    public function pkcs5_pad ($text, $blocksize) {
        $pad = $blocksize - (strlen($text) % $blocksize);
        return $text . str_repeat(chr($pad), $pad);
    }

    public function pkcs5_unpad($text){
        $pad = ord($text{strlen($text)-1});
        if ($pad > strlen($text)) {
            return false;
        }
        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad){
            return false;
        }
        return substr($text, 0, -1 * $pad);
    }

    public function PaddingPKCS7($data) {
        $block_size = mcrypt_get_block_size(MCRYPT_DES, MCRYPT_MODE_CBC);//3DES加密将MCRYPT_DES改为MCRYPT_3DES
        $padding_char = $block_size - (strlen($data) % $block_size);
        $data .= str_repeat(chr($padding_char),$padding_char);
        return $data;
    }
}
